blackIoT data sharing is one of the key services in edge networks, aiming to transfer data over a shared environment to serve end users based on edge computing. In fifth-generation (5G) and beyond networks, providing reliable and scalable blackIoT data sharing solutions to meet the increasing data usage demands of users [1]} is highly important. FLchain with its distributed learning and security nature can facilitate edge data sharing. For instance, an FLchain scheme is proposed in [2]} for privacy-preserved blackIoT data sharing among distributed multiple parties such as mobile devices in industrial IoT networks with a BS. Given a data sharing request, a multiparty data retrieval process is executed to seek the related parties (or data owners) as committees based on registration records. These committee nodes act as miners to train the global model to output the training results and then return to the requester. They also perform mining of block consisting of data sharing transactions collected over a given period of time. As a result, data owners and data requestors can achieve reliable and fast data sharing while the sharing records are stored on the blockchain for tracing. blackAnother FLchain-based blackvehicular data sharing framework in edge computing is proposed for the Internet of Vehicles (IoV) in [3]}, as illustrated in Fig. REF  with three key phases: node selection, local training, and global model computation. A node selection problem is formulated to select vehicles for local data training, which then generates model updates to build a global model. More specifically, each vehicle acts as an FL client to cooperatively share data with an aggregation server at a macro BS (MBS). Vehicles with different service demands, e.g., traffic flow estimation or path selection can submit a data sharing request to the MBS. By running a shared global model using accumulated vehicular datasets from connected vehicles, the MBS transforms the data sharing process into a computation task, in order to handle the sharing requests from vehicles with a DRL algorithm for sharing cost minimization. Particularly, to provide the security and reliability of the vehicular data sharing, an immutable blockchain ledger is deployed on the top of the edge vehicular network to implement the verification of model parameter updates and store them in blocks in a decentralized manner.
